2 way switch probs

[outinthestix]

Hi all, my parents house is an old farmhouse with fairly old wiring and an old fuse box with fuse wire type fuses. The stairs light is controlled by two way switching from their bedroom and the bottom of the stairs. Last night the fuse blew when they switched the light on so i called round as i live close by to renew the fuse wire. On switching the light on again it had blown the bulb so i replaced the bulb as well. Now the only bulb they had in was a low energy type . It switches on and off fine, but when off it flickers light every few seconds. Pulled the fuse out for the night in case it was dangerous but cant get anyone to look at it till next week and its bank holiday as well. Can any of you top blokes tell me what may be wrong and how to possibly fix it please as they are now without lights at night which is not good at their time of life ? Many thanks in anticipation of your replies STIX.

 

[Adam_151]

The failure of the lamp caused the fuse to operate, not the other way around

CFL flickering is caused by capacative coupling across the 2 way switching arrangement, and generally is not something to worry about, but things like disconnected CPCs and switches in neutral lines can magnify the amount of leakage, thats not to say that you wont get flickering in a 100% correctly wired circuit though

 

[JohnD]

if you fit an ordinary bulb it will stop flickering. It happens more often on lamps with 2-way switching and/or long switch cables.

 

[bernardgreen]

The flicker is cuased by a slight passage of current across the OFF switch due to capacitive coupling between wires goint to the switch. This is quite normal. Ordinary filament lamps are not affected by this minute trickle of current which passes through the filament without raising it's temperature anywhere near warm. But energy saving lamps save up the little trickle until there is enough to give a short flash of light.

If the wiring is very old then there may also be some leakage due to the insulation on the wire not being a perfect insulator and this may indicate a full inspection should be considered.

 

[outinthestix]

Thanks fellas, i'll put an ordinary bulb in and get it it checked by a qualified spark.